max crash using jit.gl.sketch

Hello all,
I've allready posted a crash report about using TUIO fiducial recognition app and rendering some widget using jit.render .
I've re-write all from scratch using jit.gl.sketch instead of jit.gl.gridshape. All seems to work fine but I'm facing again crashes when moving too fast the fiducials (controling widget movements) !!!
Is it well-known around there that jit.gl stuffs may crash when updating scene is too fast ?
I use the {erase , redraw all } loop each time the TUIO.app sends event . I delayed a bit the stream using speedlim but I lose some data for managing add/remove object ...
Have you people some idea for me to fix those crash problem, or is it as-is and I have to wait for the next update of jitter ...
I may use lcd instead of using open.gl , because widgets are simple geometric shapes, but how can I blend LCD with other movies or jit.matrix ? .

I gonna try also firewire external cam instead of USB ... who knows !!

I attach the patch and it's .js file, if some one please can have a look and report some tips ore mistake I made ; Thanks in advance. The js script is rough ( x,y from TUIo app not yet scaled for the screenworld , ... ), but it does what it is supposed to do as a prototype.

If necessary I can also push the crash log .

zoomak.

MacBookPro 2.33GHz, 3GB of memory, Mac os X 10.4.10 , Max 4.6.3 with up-to-date Jitter,